| Abstract : | Photometric variability studies of very low-mass stars (VLMs) and Brown Dwarfs (BDs) are an
important tool to probe the physical nature of their atmospheres. Photometric variability in these
dwarf is due to the presence of surface features like magnetic spots (strong magnetic fields) or dust
clouds, which cause optical modulation as it rotates, and it is possible to measure the period of
rotation of an object from its light curve. The time-series photometric variability is a key probe of
atmospheric inhomogeneities in VLMs and BDs. BDs are known to be rapid rotators (priod~ hours
to days), so the rotation modulation of their light curves gives information about surface features
such as magnetic spots or dust clouds, which provides an opportunity to measure the period of
rotation in these dwarfs. However, it is very challenging to detect their variability amplitude, which
is the order of a few tens milli-magnitudes. We have taken optical I-band time-series photometric
observations on a few BDs and VLMs in the Taurus star-forming region. From our preliminary
analysis of the observed data in the I-band on CFHT Tau 6 and CFHT Tau 8, we found that CFHT
Tau 8 shows significant periodic variability, and we estimate a rotation period of 6.6 hours. While
CFHT Tau 6 shows no significant variability with a given accuracy with the observed time-series I-
band data. |
